Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions

Abstract

Metal matrix composites (MMCs) with their splendid mechanical properties have been specifically designed for use in fields such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefficient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produced by squeeze casting technique. Some of the composites were aged by heat treatment. Hardness values of aged and non-aged composites were compared. In addition, abrasive wear behaviors of these composites were investigated on pin-on-disk device, depending on the load (7, 12 and 17 N), the sliding speed (0.2, 0.3 and 0.4 m/s) and the sliding distance (700, 1000 and 1300 m). Worn surfaces were also analyzed by scanning electron microscopy (SEM). As a result of the analyses, it was determined that both the hardness values and the wear resistance were higher in the composites subjected to aging treatment. Furthermore, it was observed that the increase in the applied load led up to the weight loss. The increase in the sliding distance increased both friction coefficient and weight loss. The increase in sliding speed also made way for the friction coefficient but ensured less weight loss. When SEM images were examined, it was ascertained that deformation and tribo-surface formation had a significant effect on weight losses.